United States, Illinois, Vermilion, Middle Fork Woods Nature Preserve at Kickapoo State Park, west of and adjacent to the MIddle Fork River. Danville NW 7.5 minute quadrangle.
T. 19N, R. 12W, NE1/4 SW1/4 NW1/4 NE1/4 Sect. 5
Uncommon herb on a gravel bar of the MIddle Fork River near the mouth of the large east-west ravine. With Phyla lanceolata, Cyperus spp. Uncommon in this community on gravel bars and muddy banks, not seen elsewhere.